#!/usr/bin/python
# -*- coding:utf-8 -*-



class HashSet:
    
    def add(self, e):
        self.data.add(e)
    def clear(self):
        self.data.clear()
    def contains(self, e):
        return e in self.data
    def isEmpty(self):
        return len(self.data) == 0
    def remove(self, e):
        self.data.remove(e)
    def size(self):
        return len(self.data)




